1. Field
The disclosed and claimed concept relates generally to vacuum interrupters and, more particularly, to a bellows for use in an evacuated envelope of a vacuum interrupter.
2. Related Art
Vacuum interrupters are generally known in the relevant art. Vacuum interrupters employ a set of separable contacts that are situated within an evacuated envelope to facilitate the rapid extinction of any arc that may propagate between the separable contacts when they are in the process of separating during a trip event. The two separable contacts, one being movable and the other being fixed, are situated within the evacuated envelope, with the movable contact being connected with a compressible bellows that maintains the evacuated nature of the envelope even during movement of the movable contact. Such vacuum interrupters are themselves typically incorporated into a vacuum circuit interrupter that employs a separate vacuum interrupter on each pole.
While such bellows have been generally effective for their intended purposes, they have not been without limitation. When the set of separable contacts are separated from the closed state, or closed from the open state, the movable contact moves with great speed and thus energy, meaning that one end of the bellows is rapidly accelerated and then rapidly decelerated, while the opposite end of the bellows remains fixed. Since the bellows typically are formed of a thin metal, such bellows have been sometimes known to rupture due to their inability to withstand the mechanical forces inherent in the separation of the separable contacts, repeatedly, for tens of thousands times. It thus would be desirable to provide an improved bellows that meets these and other needs.